How to send python class objects using flask and pickle

Question

I have the following code

client.py

import requests
import pickle

class Test():
    def __init__(self, val):
        self.val = val

testList = []
for i in range(0,10):
    testList.append(Test(i))



data = {"foo": 1000, "bar": "value", "list": testList}
endpoint = "%s/%s" % (address, "testendpoint")
r = requests.post(endpoint, data={"req": pickle.dumps(data) })

server.py

import flask
import pickle
from flask import request

app = flask.Flask(__name__)
app.config["DEBUG"] = False

class Test():
    def __init__(self, val):
        self.val = val

@app.route('/testendpoint', methods=['POST'])
def testendpoint():
    data = pickle.loads(request.form['req'])
    print(data)

    response = {
        "response": "Success"
    }

    return json.dumps(response)

app.run(host="0.0.0.0", port=24979)

When I run client.py with server.py running, I get the following error:

[2020-07-17 14:06:05,054] ERROR in app: Exception on /testendpoint [POST]
Traceback (most recent call last):
  File "/usr/local/lib64/python3.6/site-packages/flask/app.py", line 2446, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/local/lib64/python3.6/site-packages/flask/app.py", line 1951, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/local/lib64/python3.6/site-packages/flask/app.py", line 1820, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib64/python3.6/site-packages/flask/_compat.py", line 39, in reraise
    raise value
  File "/usr/local/lib64/python3.6/site-packages/flask/app.py", line 1949, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/local/lib64/python3.6/site-packages/flask/app.py", line 1935, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "server.py", line 11, in testendpoint
    data = pickle.loads(request.form['req'])
TypeError: a bytes-like object is required, not 'str'

I assume my bytes object gets converted to a string when sent via the http request. How do I send my data on the client via the request and then decode it on the server end?

Sending pickled objects like this should probably be avoided. See here and here for various solutions/explanations. — v25
– v25, Commented Jul 17, 2020 at 22:26

Ariuan Chips · Accepted Answer · 2021-04-04 14:10:25Z

0

It should be dumps, but not loads

Edit like this

data = pickle.dumps(request.form['req'])

answered Apr 4, 2021 at 14:10

Ariuan Chips

291 silver badge4 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to send python class objects using flask and pickle

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related